if at one hundred miles, one orbit takes an hour and a half; if we go up to 22,300 miles, one orbit takes twenty-four hours. So what? Well, the earth also takes twenty-four hours to go around once, so that the 22,300-mile satellite will stay over the same spot on the ground, i.e. be synchronous with the earth’s rotation, which is fiendishly clever if you want to use it as a communications-relay satellite. Interesting applications of boring equations.
